Nuclear reactors of the graphite/gas type, which are moderated by graphite and cooled by carbon dioxide gas, comprise fuel elements arranged in graphite jackets of tubular shape, comprising, at one of their ends, stainless steel wires which are implanted in the thickness of the graphite jacket and are mutually perpendicular.
The stainless steel wires, "saddle wires", are intended to hold a graphite part termed the "saddle" in the central part of the jacket.
After a certain length of use inside the core of the nuclear reactor, the fuel element jackets must be removed and replaced.
Because of their time spent in the core of the nuclear reactor, the jackets are activated, so that it is necessary to take certain precautions to dispose of them.
Although the graphite of the jackets is moderately activated, the same is not true of the stainless steel constituting the wires, which has very high activity because of the nature of its constituents.
It is therefore desirable, in order to dispose of the jackets for fuel elements under satisfactory conditions, to separate the graphite from the stainless steel wires, so as to store and dispose of the two constituents of the jackets for fuel elements separately.
One of the factors making it possible to facilitate separation of the graphite and of the stainless steel wires is that the stainless steel of the wires is a magnetic steel and that graphite is non-magnetic.
To date no method and device are known which make it possible to process such jackets for fuel elements, with a view to their disposal, automatically and efficiently.
More generally, no method and device are known which make it possible to process and dispose of activated elements comprising two constituents having substantially different magnetic characteristics and activation levels which are also different.